Many designs have addressed the difficult challenge of obtaining vertical or short takeoff or landing in fixed wing aircraft with high-speed cruise capability. The designs have included two separate power sources (one for vertical thrust and one for horizontal) (see U.S. Pat. Nos. 4,469,294; 3,083,935 and 3,388,878); ducted fans mounted in the fixed wings which rotate from horizontal to vertical (see U.S. Pat. No. 3,335,977); diverting jet engine exhaust turbo fans mounted above fixed wings and transitioning exhaust, through ducting from vertical to horizontal (see U.S. Pat. No. 3,972,490) and the numerous tilt wings and tilt engine concepts configured from the late 1930s to today.
Other prior designs have driven ducted fans or ducted propellers from turbo-prop or pure-jet engines by venting the exhaust gases to turbine blades attached to the outer edges of the fan or propeller assemblies as in U.S. Pat. No. 3,972,490. Previous patents also have used mechanical drives for the ducted fans or ducted propellers, which entailed long drive shafts (and even belt drives) with complex gear box assemblies (see U.S. Pat. No. 4,469,294.)
All of these embodiments involve at least one of the three most troublesome aspects of V/STOL aircraft designs. They may involve:
1) Cumbersome, and therefore heavy, mechanisms for moving massive structures such as wings or ducted fan assemblies; or
2) Sacrificing aerodynamic smoothness, thereby creating unacceptable drag; or
3) Multiple power plants or complex drive trains, thus increasing weight and lowering performance.
The goal of the present invention is to avoid all of these previously mentioned troublesome elements of V/STOL designs while maintaining good performance during horizontal flight (the ultimate intended configuration of all V/STOL aircraft.)